|
1. Definition
| Name |
CLIMATE
QUALITY INDEX |
| Brief definition |
This index
is calculated using classifications of the following parameters:
rainfall, aridity index(1), and aspect. |
| Unit of measure |
CQI = (rainfall*aridity*aspect)**1/3 |
| Spatial scale |
Regional |
| Temporal
scale |
Annual,
for rainfall |
2. Position
within the logical framework DPSIR
3. Target and
political pertinence
| Objective |
To
condense knowledge about climate properties into an index that
can be used on its own or in conjunction with other quality
indexes associated with desertification. |
| Importance
with respect to desertification |
The uneven
annual and interannual distribution of rainfall, the occurrence
of extreme events and the out of phase nature of the rainy and
vegetative seasons, in the semi-arid and arid zones of the Mediterranean
ar the main climatic factors that contribute to the degradation
of land. Global climate change is expected to widen the present
geography of the vulnerable zones in the Mediteranean. |
| International
Conventions and agreements |
A variety of
transboundary legislation exists, including the United Nations
Convention to Combat Climate Change, as well as EC directives.
|
| Secondary objectives
of the indicator |
To contribute
to an overall measure of sensitivity to desertification in the
classification of Environmentally Sensitive Areas and the ESI. |
4. Methodological
description and basic definitions
| Definitions
and basic concepts |
Climate quality is assessed
by using parameters that influence water availability to plants,
such as amount of rainfall, air temperature and aridity, as
well as climatic hazards such as frost that inhibit or even
prohibit plant growth.
The atmospheric conditions
that characterise a desert climate are those that create large
water deficits, that is, with potential evapotranspiration
(Eto) much greater than precipitation (P). Amount of annual
rainfall affects soil erosion. In hilly Mediterranean shrublands,
where annual rainfall is greater than 300mm/year there is
a tendency towards increasing run-off and sediment loss with
decreasing rainfall. Below the 280 mm annual rainfall limit
run-off and sediment loss decrease with decreasing rainfall.
Rainfall amount and distribution determine biomass production.
Decreasing amounts of rainfall combined with high rates of
evaporation drastically reduce the soil moisture content available
for plant growth. Reduced biomass production, in turn, directly
affects the organic matter content of the soils, and the aggregation
and stability of the surface horizon against erosion.
The Bagnouls-Gaussen bioclimatic
aridity index relates mean air temperature to precipitation
on a monthly basis and provides a measure of water stress
in the vegetation. Vegetation cover increases with increasing
soil depth and decreasing aridity.
Slope angle and general
topography are also important determinants of soil erosion.
Erosion becomes acute when slope angle exceeds a critical
value and then increases logarithmically. Slope gradient may
have a different effect in different climatic zones, depending
on annual rainfall. On the Greek island of Lesvos severely
eroded soils are present in the semi-arid zone with slopes
greater than 12%, while slightly to moderately eroded soils
are found in the dry sub-humid zone under the same slope classes.
|
| Benchmarks
Indication of the values/ranges of value |
According to
the class of each climate quality indicator (rainfall, aridity,
aspect) a numerical value is assigned. The geometric mean of
the three climate quality indicators is calculated. Three classes
of Climate Quality Index are then distinguished: high quality,
moderate quality, and low quality. For ranges of weighting indices
see Kosmas, Kirkby and Geeson, 1999. |
| Methods
of measurement |
Climate Quality Index
= (rainfall*aridity*aspect)**1/3.
For the components of
this calculation, 3 classes of annual rainfall, 6 classes
of aridity (from the Bagnouls-Gaussen Index), and 2 classes
of slope aspect must be assessed.
|
| Limits of the
indicator |
The Climate
Quality Index has been developed particularly for the Greek
island of Lesvos, and the weighting indices may require adjustment
for other areas. |
| Linkages with
other indicators |
Rainfall,
Slope aspect, Aridity
index(1), Vegetation
quality index, Management
quality index, ESI |
5. Evaluation
of data needs and availability
| Data required
to calculate the indicator |
Data are required
relating to 3 classes of annual rainfall, 6 classes of aridity
(from the Bagnouls-Gaussen Index), and 2 classes of slope aspect. |
| Data sources |
Basic climate
information is usually available in a cost-effective format. |
| Availability
of data from national and international sources |
Data
can be obtained from national agencies and various regional
institutions involved in collecting and processing data. |
6. Institutions
that have participated in developing the indicator
| Main institutions
responsible |
Agricultural
University of Athens, Greece |
| Other
contributing organizations |
Universities
of Lisbon, Murcia, Basilicata |
7. Additional
information
| Bibliography
|
Kosmas,
C., Kirkby, M. and Geeson, N. 1999. Manual on: Key indicators
of desertification and mapping environmentally sensitive areas
to desertification. European Commission, Energy, Environment
and Sustainable Development, EUR 18882, 87 p. |
| Other references |
Brandt, J., and Thornes,
J., 1996 Mediterranean Desertification and Land Use. J. Wiley
& Sons, Chichester, England, 554.
Kosmas C., Ferrara A.,
Gerontidis, St. Bellotti B., Detsis V., Faretta S., Mancino
G., and Pisante, M. 1999. A comparative analysis of the physical
environment of two Mediterranean areas threatened by desertifciation.
Mediterraneo M. 127-148.
Conacher, A., and Sala,
M., 1998. Land Degradation in the Mediterranean Environments
of the World: Nature and Extent, Causes and Solutions. J.
Wiley & Sons, Chichester, 491 p.
|
| Contacts
Name and address |
Dr.
Constantinos Kosmas
Agricultural University of Athens, Greece
email: lsos2kok@aua.gr |
|
